| ORGANIC CHEMISTRY I CHEM 2323 |
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| ORGANIC CHEMISTRY I CHEM 2323 |
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CYCLIC ALIPHATIC COMPOUNDS
Ring compounds are also referred to as alicyclic compounds and aliphatic cyclic compounds.
Homocyclic - only one element in the ring (example: all carbons).
Heterocyclic - more than one type of element in the ring (example: carbon and nitrogen)
1. Count the number of carbons in the ring (example: 4).
2. The prefix is cyclo followed by the respective straight chained alkane name (cyclobutane).
3. If there is a single side group on the ring (monosubstituted), assume it is the number one carbon.
4. If there is more than one side group, use the lowest possible numbers.
5. If there are two different side groups (disubstituted), number alphabetically.
6. If there is a double bond and a side group, the double bond gets priority (#1 - 2 is assumed), and the side group gets the lowest possible number after that.
7. If there is a double bond and an alcohol group, the alcohol group gets priority.
A quicker way to draw rings is to use stick figures where unless indicated otherwise, each junction of two lines represents a carbon.
INDUSTRIAL SOURCES
PREPARATION OF CYCLIC COMPOUNDS
Cyclic compounds are normally make via one of two general methods.
1. conversion of a straight chain into a ring (cyclization)
2. conversion of one cyclic compound into another.
Cyclic aliphatic compounds normally undergo similar reactions as other straight chained aliphatic compounds.
REACTIONS OF SMALL RING COMPOUNDS
angle strain - deviations from 109.5 degree tetrahedral
torsional strain - deviation from staggered bonds
steric strain - van der Waal repulsions
STEREOISOMERISM OF CYCLIC COMPOUNDS
Crown ethers contain 4 or more oxygens within the ring.
